


Becoming Boss

by Lingeringchaos



Series: Nothing Left To Save [1]
Category: Undertale (Video Game)
Genre: Alternate Universe - Underfell, Angst and Hurt/Comfort, Babybones (Undertale), Bad Puns, Brothers, Child Abuse, Children as test subjects, Cute Kids, Disturbing Themes, Experimentation on Children, F/M, Fluff, Fuku is Grillby's daughter, Gaster is a bad dad, Growing Up, How Do I Tag, Minor Character Death, Protective Sans, Sans being a bad brother, Sans being a good brother, Science Experiments, Scientist W. D. Gaster, Swearing, Time Skips, Underfell Papyrus, Underfell Sans, Underfell W. D. Gaster, Undyne has a brother, W. D. Gaster Being An Asshole, Will tag as I go along, handplates inspiration, sans tries his best
Language: English
Status: In-Progress
Published: 2018-01-31
Updated: 2018-02-18
Packaged: 2019-03-11 19:44:00
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 3
Words: 12,157
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13531236
Author URL: https://archiveofourown.org/users/Lingeringchaos/pseuds/Lingeringchaos
Summary: Papyrus wasn't always The Great and Terrible Captain of the Royal Guard. Sans wasn't always a nervous mess who could hardly summon his magic. Here we see the rise of one brother and the fall of the other.***ON HIATUS***





	1. Warning sign

**Notes for the Chapter:**

> I'm bad at summaries.
> 
> I have entirely too many Underfell headcanons, so here we go, let's start from the beginning!

  _And I'll use you as a warning sign_

  _***_

Sans

 Sans walked side by side with the doctor, his white eyelights staring at the tiled floor with a mutinous expression. The doctor was in a particularly good mood today, which was not only unusual, but down right distressing. Sans had noticed that the doctor’s right hand was heavily bandaged, making the doctor favor the left, the one with the hole in the palm. The doctor avoided using that hand at all costs. _Usually_ when Gaster was sporting an injury he was downright cruel, which made the scientists current good mood even more unnerving.

 So, Sans had been extremely suspicious when the experiments Gaster had had Sans perform this particular day were quick, easy, and ones Sans tended to enjoy. (Solving equations, doing mathematical problems, and timed puzzles). Usually when the doctor was injured he took out his frustration on Sans with the more unpleasant tests. (The DT injections, pushing Sans’s stamina, measuring Sans’s adrenaline, etc.). So, when the doctor said he had a ‘surprise’ for Sans, Sans knew it couldn’t be anything good and that he had every right to have been suspicious all along.  

 Sans sighed softly, slowing his pace. The last ‘surprise’ Doctor Gaster had in mind for Sans involved a floating dog like skull that he had tethered to Sans. Sans wasn’t sure what the doctor meant by tethered but It had been an incredibly painful process that had made every bone in Sans’s body ache. What was worse is that Sans couldn’t control the stupid dog skull. It liked to appear out of thin air when Sans was upset and blast things or unfortunate bystanders with a beam of white laser death. In other words, the stupid skull appeared only to get Sans into serious trouble. Sans was constantly punished for something he couldn’t even control and Sans hated it. He was sure he’d hate this new surprise as well.

 “In here,” Dr. Gaster said opening Room 1-A. Sans frowned up at the doctor who gave him an impatient look. This was one of the medical rooms. Sans had been here countless times, usually when he was injured, ill, or due for shots, or worse, DT injections. He really hoped he wasn’t going to get an injection today. He had just had one two days ago.

 What Sans did _not_ expect as he scowled and looked around the room was to see a strange white bassinet by the medical exam table. Dr. Gaster gave a tired sigh walking over to it, motioning for Sans to follow. Sans warily walked over and peeked in. Wide white eyelights met Sans’s.

 A very small skeleton was peering up at Sans. Sans didn’t’ even know a skeleton could be that tiny. Sans stared in wonder as the little creature squealed and a skeletal hand so much smaller than Sans’s own immediately reached for him.

 “What is it?” Sans asked softly.

 “Sans, this is your brother,” Gaster said and he looked down at the skeletal infant with an expression Sans rarely saw. The expression involved a soft smile with white eyelights instead of the doctor’s trademark crimson. It wasn’t a bad expression, but Sans couldn’t figure out what it _meant_. If Sans was particularly clever in an experiment or test he sometimes received the same look. Sans would _like_ to think it was an affectionate look. _But he knew better than that._

  “You’ll help me take good care of him, yes? I'm a very busy monster and I don’t have time to watch him all the time.” Dr. Gaster said gesturing to the baby. Sans looked at the small skeleton again. The baby babbled happily, and grinned wide his white eyelights curious and big. Sans couldn’t help but smile back.

 The baby cooed and reached out towards Sans again. Hesitantly Sans stepped closer and a tiny skeletal hand wrapped around one of his phalanges. Sans smiled down and the baby squealed happily.

 “I-I’ll help take care of him,” Sans said scratching the back of his skull. He tried to pull his hand away, but the baby’s grip was stronger than Sans expected. The tiny fist around Sans’s index phalange refused to let go. Sans didn’t want to hurt the tiny skeleton, so he let his hand stay.

 “Good.” Gaster said watching Sans with a lazy expression. Sans stared down at the small creature. _His brother._ Sans had a brother. Sans was a big brother.

 “What’s his name?” Sans asked softly before looking up at the doctor who had begun to nod off.

 “Mm,” Gaster said and he frowned slightly, blinking. “I haven’t thought of one. Why don’t you name him?” Sans spluttered his sockets going wide.

 “M-me!?” Sans echoed in shock. The doctor actually chuckled at that an amused smile on his scarred face.

 “Yes. Go on. He needs a good, strong, name.” Dr. Gaster leaned forward staring at Sans expectantly. Sans swallowed hard before looking back down at the smiling baby bones.

 “Uh… what about….”

 ***

5 years later

 W.D. Gaster

 “PAPYRUS, _you little shit_! When I find you, I’m going to kick your fucking ass!” The very ‘esteemed’ and ‘proper’ Dr. Gaster snarled before tearing the door off of one of the medical supply cabinets with his bare hands. The angry five-year-old skeleton was surely hiding inside of the cabinet. He had to be, right? Gaster dug his long arms in feeling a small skeletal foot kick him. Gaster heard Sans snort loudly behind him.

 “Yeah. Cuz _that’ll_ make him come out,” Sans drawled lazily spinning around in a medical exam chair.

“ _You_ were supposed to be watching him!” Gaster snarled his dark red eyelights flashing at Sans furiously. Sans shrugged, not looking threatened in the least. “I _was_ watching him Doc. I watched him run in here. Didn’t I do a bang-up job? That's quality watching skills my friend.”

 “I swear to Asgore! Sans, I am _not_ in the mood for your fucking attitude-”

 “Shoulda just kept me in a test tube until I was an adult then. Shoulda known what a delight I’d be in my teens,” Sans grinned nastily. “Musta got that from _you_ -”

 “I’ll fucking melt you down and start from scratch you ridiculous piece of-” The doctor’s sentence was cut off as he yelped in pain. A tirade of swears spewed from the scientist as he jumped back from the cabinet. The five-year-old skeleton they had been searching for had indeed been hiding in the cabinet and had just sunken his very sharp teeth into Dr. Gaster’s ulna. Sans’s white eyelights lit up mischievously.

 “Hey Doc? I found Papyrus,” Sans said with a shit eating grin. “He’s right there.” Sans gestured at the growling small skeleton whose fangs were imbedded into the doctor’s arm.

 “Stars dammit Sans! Shut up! Papyrus! _You will release me at once!_ ” Gaster snarled giving Papyrus what Sans had dubbed expression #4. Gaster had been informed by Sans that he apparently only utilized four expressions. Number 1 was lazy, 2 was tired, 3 was amused/ happy, 4 was pissed off, and 5 was ‘holy shit run everyone is gonna die’. Gaster liked to point out that that was more than five expressions to which Sans would usually tell Gaster to "fuck off". Gaster would have asked Sans who taught him such vulgar language, but he was afraid the answer was him.

 Papyrus growled his jaw clenching tighter. Gaster drew in a long, slow, breath praying to any deity that may be listening, the angel, whatever, that he would keep his patience. Usually Papyrus was such an agreeable child. Truly, he was downright sweet. But Papyrus had _not_ taken well to the experimentation yesterday. Not at all.

 How do you explain to a five-year-old that testing their ability to withstand pain will benefit monster kind? How do you explain to a five-year-old child that you weren’t _hurting_ their brother when they walked in on their brother screaming in agony as another injection of determination was halfway through, but that you were _helping_ their brother? How do you explain to a five-year-old that shaving their finger bones and teeth to sharp points is a necessary (but extremely painful process) for self-defense?

 You couldn’t. He couldn’t, and this was the third time the little shit had hidden from him today. It was the first time Papyrus had _bitten_ him though. Gaster was deeply regretting sharpening the small skeleton’s teeth as he frowned at the small rivers of marrow that steadily trickled from where Papyrus’s teeth were still embedded into his ulna.

 “Papyrus. **Let. go**.” Gaster commanded adding a harsh edge to his voice. Gaster preferred to keep his tone calm and calculated, monotone even, but that hardly got him the responses needed from the difficult skeleton children. Papyrus hesitated for just a moment before he unlatched his sharp teeth from the doctor’s ulna, his white eyelights full of betrayal.

 “Why’d you hafta hurt Sans?” Papyrus glared at him accusingly.

 Gaster tried to stay angry, he really, really did. But the soft spot he had for Sans and Papyrus was an increasingly growing problem. The fact that Papyrus was being difficult for Sans’s sake instead of his own both was baffling and endearing to the doctor. He wasn’t used to the innocent affection the brothers had for each other, or the selfless way each cared for the other. It was maddening. It was confusing. Worst of all, _it made him feel things._

 Gaster sighed. He should be disciplining Papyrus. That bite was definitely going to scar, and he couldn't have - ~~his boys~~ \- his experiments misbehaving in such a way.

 “Come here.” It wasn’t a request, but Papyrus tried to run away anyway. Gaster gripped the small monster’s shirt collar and pulled Papyrus into his lap and hugged the small child. Papyrus froze for a moment before melting into the hug. It wasn’t often Gaster showed affection. He was not an affectionate monster and found Sans’s neediness in his earlier childhood exhausting and frustrating. But Gaster had learned from Sans that it was easier to get what he wanted with the occasional expression of affection over his usual stoic demeanor.

 “I wasn’t hurting Sans just to hurt him, Papyrus. It’s to make Sans stronger.” Gaster explained.

 “Sans is already strong,” the child huffed glaring up at Gaster accusingly.

 “In some ways, yes. But his stamina and HP are considerably lacking and put him at risk,” Gaster said and he fought the tug at his mandible that wanted to smile as Papyrus’s eyelights glazed over as they always did whenever Sans or Gaster talked about things that were too complex for him to grasp.

 “I’m fine bro, really,” Sans grinned spinning in his chair again.

 “There you are.” The curt sharp voice of Gaster’s least favorite person cut through the room. Sans bristled, and Papyrus cringed in Gaster’s arms.

 “Dr. Osa. I didn’t hear you slither in,” Gaster sighed looking over at his colleague. She was hooded, as always, in a long black cloak. Her gaunt blue skinned skeletal like hands were the only visible features she ever graced anyone, though Gaster had had the ‘pleasure’ of seeing what lurked beneath the cloak and hood.  

 Gaster couldn’t blame her for hiding her features. The war with the humans had been _so_ long ago. She was the last of her kind, much like Gaster was the last of his. They both got very odd glances, and the occasional threat from over defensive monsters. Gaster glanced at the small skeleton in his lap and he smiled. Gaster was no longer the last skeleton. It was so easy to forget.  

 “Very funny,” Osa huffed crossing her arms. “King Asgore is displeased. The DT experiments have little to no results and he wants P-7, U-6, and B-4 to start injections immediately. S-4 is a failed experiment.” Sans let out a low growl from his chair.

 “S-4’s injections are almost complete. There are six more. It is worth pursuing. There has been progress, though not as we had hoped,” Doctor Gaster sighed avoiding San’s hurt gaze. “P-7 and U-6 are too young. B-4 is part of the S O U L experiments, it would be unwise to cross him over,” Gaster finished. Sans had stiffened and was gripping the arms of the chair hard enough for it to crack and Gaster shot him a warning look. Osa sighed crossing her thin arms.

 “Their age is of no consequence. What should their mental states matter in the name of science? You’re just too _soft._ Don’t you see what these children are doing to you? Making you weak. You let yourself get to close, particularly to these two,” Osa scoffed and gestured to the young skeletons.

 “I did not.” Gaster lied. He stood up to his full height. Papyrus squeaked in shock as he slid from Gaster’s lap and onto the floor. Gaster scowled down at Dr. Osa towering over her. “I merely saw what happened to _your_ experiments and decided another course of action was needed.” Osa, wisely, took a step back. Oh, Gaster remembered the gaunt eyed slow-moving husks of orphans Osa had had at her disposal. It was _not_ something Gaster planned to replicate.

 Her SOUL enhancement experiments had technically been a success, in that the children’s souls were enhanced. However, the children had lost the ability to emote, speak, and think other than following basic direct orders. The children at her disposal had been listless shells of monsters. As Gaster had just finished the CORE at the time of her failure, her DT experimentation assignments had been passed on to him as the children had all _melted_.

 Osa literally growled and Gaster smiled nastily.

 “Just stop coddling them. They’re putting your work at risk. They’re experiments! _Things_. You seem to be forgetting that,” Osa scoffed and she gestured to Sans. “ _That one,_ is a failed experiment. The DT doesn’t seem to be affecting it in the least.  It should be put down. Its growth is stunted, its HP is deplorable-”

 “Ya calling me short?” Sans spun in his chair once more before giving the doctor a lazy grin as his eyelights scanned the woman. “Hey Osa, you’re pretty tall, huh? I didn’t know they stacked shit that high.”

 “You little bastard!” Osa snarled. Osa was fast, but Gaster was faster. He stepped in between Sans and Osa, the glowing blue pits of fire within her hood narrowed and the ice wisps around her hands dulled.

 “What do you think you’re doing? S-4 has _six_ injections left and 1 HP. You will dust him if you strike him, and you will be the one to explain to King Asgore why the first DT experiment was destroyed before it saw its conclusion!” Gaster growled furiously. A hissing noise escaped Osa and she clenched and unclenched her gray-blue fists before taking a step back.

 Sans gave Osa a shit eating grin. “Geeze doc, don’t need to be such a _fire_ cracker,” Sans winked at Osa. The twin blue fire pits narrowed within her hood. Gaster turned sharply and grabbed Sans roughly by his shirt collar.

 “Ah- hey- shit-” Sans cursed and Gaster slammed the fourteen-year-old against the wall, hard.  Papyrus squeaked in shock before running over.

 “Put him down! Don’t hurted him!” Papyrus growled and stomped his foot. Gaster ignored the smaller, angry skeleton and scowled at the eldest of the two.

 “Apologize to Dr. Osa. Now.” Gaster hated this. Frankly, he loved that someone stood up to Osa other than him, but he couldn’t have Sans treating faculty like that. Even Osa.

 “No!” Sans scowled. “She’s a bitch!” Gaster scowled. Why did Sans have to be so _difficult_? Gaster did not want to hurt him but Sans was giving him little option, especially with Osa hovering over his shoulder.

 Gaster felt wisps of crimson magic leave his right socket and he cracked the back of his hand across Sans’s face. Sans’s eyelights shrank and his breath hitched.

 “Apologize. **Now, S-4.** ” Gaster growled.

 “. . . _Sorry_ , Doctor Osa.” Sans said through grit teeth. Gaster dropped Sans to the floor and the teenager landed on his feet, glaring at Gaster furiously. Papyrus growled at Gaster, standing in front of Sans as if shielding him. Gaster had to look away. That was adorable.

 "How do you do that without effecting his HP?” Osa drawled, cocking her head to the side curiously.

 “You’re a scientist, I’m sure you’ll figure it out eventually,” Gaster crossed his arms. Osa huffed and turned to the door.

 “You need to get it together Wingdings,” Osa said her voice softening slightly. “It’s for all of monster kind that we do these experiments. A handful of children's lives are nothing compared to all of monster kind. Stop coddling your experiments. You can’t afford to care.” Osa left the room with a slam of the door.

 Gaster scowled after her.

 “I hate that witch,” Sans growled out. Gaster frowned down at him and Sans froze, a look of panic forming in his eyelights.

 “You need to be more respectful to the staff,” Gaster said with no real heat. The fear vanished from Sans’s white eyelights and anger took its place.

 “Respectful. Staff. Right. So, I’m a failed experiment huh? Gonna dust me after my last six injections?” Sans scowled up at the royal scientist before rubbing his bruised cheekbone with the back of his hand.

 “Don’t be ridiculous, Sans. You’re not a failed experiment. You’re my greatest achievement.” Sans blinked looking taken aback, before his eyelights fell to the floor, his cheekbones turning red from the praise.

“Besides you’re highly intelligent. Far more intelligent than those drooling fools they’ve assigned as lab assistants for me,” Gaster said shaking his head. “After the DT injections are finished, if Osa believes you’ve outlived your usefulness, well, you’ll just become my new lab assistant. Won’t that piss the bitch off?”  

 Sans grinned his white eyelights lit in amusement.

“Now take your brother back to the west wing,” Gaster instructed. Papyrus, who was still glaring at Gaster angrily, growled, low from the back of his throat. Gaster wasn’t used to his youngest experiment being so aggressive, but it was an interesting development. He would have to monitor the young one’s behavior.

 “I’m fine bro, come on,” Sans gently gripped the five-year-old’s shoulder.

 ***

Sans

 Sans quickly led his brother down the hall from the offices, through the dining room and towards the hallway to the far left. The moment the door closed behind them the tension seemed to seep out of Sans’s bones. The west wing was the only area Sans ever truly felt safe within these labs. It was where the test subjects slept and spent their free time, and usually, nothing too terrible happened here.

 Papyrus sulked scuffing his shoes against the polished wooden floor.

 “What’s wrong bro?” Sans looked down with worry at the smaller skeleton.

 Papyrus looked up sliding his small fingers between Sans holding his hand tightly. “Gaster,” Papyrus said his sockets squinting. “Why’s he so mean all of a sudden?”

 Sans sighed glancing down at the small skeleton.  He supposed it would seem to Papyrus, like Gaster was “suddenly” mean. Papyrus was young. Even doctor Gaster wouldn’t subject such a young child to harmful or painful experiments, so Papyrus hadn’t received any of the less desirable experiments and tests, until yesterday.

 The bone sharpening was supposedly necessary. Sans sighed, maybe it was. The little heathen Undyne had beaten Sans’s brother up more than once and now he’d be able to defend himself with the sharp claw like tips his finger bones had been carved into.

 The measuring pain tolerance, in Sans’s opinion, had defintely not been a necessary thing, but Sans was sure Gaster hadn’t done anything too awful to Papyrus. Gaster despite being an absolute dick, truly seemed to have a soft spot for the skeleton brothers. Still, Sans had tried to put the start of Papyrus’s more challenging experiments off, arguing that Papyrus was still too little, that it would emotionally scar him and mess up his ‘development’.

 Gaster of course had waved him off, promising he wouldn’t do anything to damage Papyrus. Sans wasn’t so sure.

  _He hasn’t damaged you yet has he?_ Sans asked himself. He supposed not? Although he _hated_ the DT project. It was painful, but it didn’t seem to do anything besides hurt. Six more injections and he’d never have to have another one. He couldn’t fuckin’ wait.

 “Sans?” Papyrus frowned up at him. Shit, right, Papyrus had asked him a question.

 “Gaster is. . . he’s kinda a jerk Paps. He was nice to you cuz you were a babybones, but you’re a big boy now right?”

 Papyrus’s sockets widened, and he crossed his arms. “Of course I am!” Papyrus huffed. Sans grinned.

 “Well, big kids have to do the more important experiments. Sometimes they hurt. . .but it’s to help all of monster kind,” Gaster’s words tasted like acid in Sans’s mouth. As if that really justified the things the scientist did.

 Not that Gaster had done anything truly awful to Sans or Papyrus. But Sans had seen what the doctor was capable of on his not so favorite test subjects, and it scared him.

 “So, as you get bigger, the experiments get a little harder. It might hurt a bit sometimes, or be boring, but, you can do it. Your very great after all,” Sans said.

 “I am?” Papyrus asked.

 “Of course, you’re my brother, and only the greatest person could be brother to the magnificent Sans,” Sans winked at his brother who grinned wide.

 “Yes! I’m the Great Papyrus!” Papyrus bounced on the balls of his feet.

 “Exactly,” Sans said, giving his brother a fond look. The experiments were going to get harder. Increasingly unpleasant. But Sans would _never_ allow Gaster to truly hurt his brother. Ever. Papyrus would _never_ undergo the DT injections. Over Sans’s dust would that happen.

 Sans pushed the ‘Activity’ room open. One of the scientists, perhaps even Gaster, had decided that the test subjects needed an outlet for their energies. The activity room was a gym of sorts. It had ropes to climb, punching bags, a jungle gym of sorts. Exercise was important or some nonsense. The children didn’t get toys, but they got an area to run around and practice their magic, their attacks, and spend their energy. Sans much preferred the library. He spent most of his free time there, reading.

  _I won’t have stupid test subjects. If you must speak to me, and I wish you wouldn’t- why must you incessantly pester me? Ugh.  Because I know you will continue to start conversations with me, you will sit in here and read so you’ll have something worthy and of interest to talk about._

 Sans shook his head chasing away the memory of the first time Gaster had dragged Sans to the library. Sans eyed the activity room warily and glanced down at Papyrus who was already bouncing with excitement. As Sans was fairly lazy, he was certain the cause of the activity room originally laid blame in Beta. Beta was the one who had been here the longest, second to Sans of course, and he had more energy if not less than when he first arrived at the age of four. But now Papyrus could enjoy it and Sans could sit in the corner and take an overdue nap.

 “Sans!”

 Speak of the devil. Beta waved before continuing to crash his fists into the punching bag in front of him and it swung vicariously. The fish monster dwarfed Sans by about 2 feet now, though the little punk had been shorter than him when he first arrived. His red mohawk was the most eye-catching thing about him, next to the height. His scales were a deeper color than his sister’s, his were more of a purple color, like eggplant. He and his sister shared the same fierce eye color though. They resemble each other more than Sans and Papyrus resembled each other, something Sans was always jealous of, not that he’d ever admit it.

 Beta’s sister peered from the side, yellow eyes wide with admiration toward her older brother. Undyne. She was around Paps’s age and the two liked to play together, which was great, Sans didn’t have to chase his hyperactive brother all around the room. Undyne was just as active (and violent) as her brother, Beta and it was good Papyrus and she wore each other out. Less work for Sans.

 “Yo,” Sans greeted Beta with a wave of his hand. He nudged Papyrus softly. “Go play with ‘Dyne.” Papyrus grinned up at him and ran to the small fish girl, who grinned excitedly at him.

 “You can’t catch me!” She yelled, and she darted under the jungle gym. Papyrus chased after her the two giggling. Sans couldn’t help but watch fondly.

 “How’s your bro doin’?” Beta wiped the sweat from his brow with a cloth and had walked over to Sans. Sans met the fish boy’s yellow eyes.

 “He’s taking things pretty well,” Sans said with a shrug.

 “Undyne’s still upset about her teeth getting sharpened and your bro got it worse. Fingertips too, right?” Beta frowned.

 “Yeah.” Sans sighed. Sans wasn’t sure why test subjects needed sharpened teeth and make-shift claws. It’s not like they were ever going to get out of here. Who posed a threat to the test subjects? The last lab assistant who had dared injure one of Doctor Gaster’s test subjects had faced the scientist’s wrath. Gaster had gathered all of the scientists and lab assistants and had _dissected_ the unfortunate lab assistant still living, with no anesthetics in front of them. It took hours for that poor bastard to dust and several of the lab assistants had resigned that very day. One of ‘em even fainted during the ‘procedure’.

 No one was going to be stupid enough to lay a hand on any of them after that shit show, so why did they need sharp teeth and claws to defend themselves when they had Gaster’s reputation to do it for them?

 Beta sighed, drawing Sans’s attention away from his thoughts. “I wish they’d leave ‘Dyne and Paps alone.” Beta said, a sharp edge rising in his voice.

 “Me too,” Sans admitted watching the two children in question giggle and play.

 “I hear the kids under Doctor Alphys’s experiments are treated better,” Beta huffed. Sans didn’t doubt it. He’d met the yellow scaled doctor a few times. She was quiet, and nervous, especially so around Doctor Gaster, but she had given Sans candy and let him watch anime instead of giving him a physical like she was supposed to the one time so she was okay in Sans’s book.

 “Don’t think Doctor Gaster’ll trade us with Alphys’s subjects, do you?” Sans said with a grin. Beta snorted.

 “Yeah. Sure. Right after Dr. Osa knits us all sweaters and bakes us cookies,” Beta said. Sans grinned leaning against the wall next to his friend. It could be worse though, right? This wasn’t that bad. He heard horror stories of what life was like outside the lab. Maybe things were better in here?

 “Hey, I wanna show you something,” Beta said before glancing at Undyne and Papyrus warily. “Yo! Dyne, Papyrus. Stay in here, we’ll be right back, yeah?” Beta called.

 “Whatever,” Undyne said before pouncing on Papyrus from the top of the jungle gym like a lion would its prey. Papyrus screeched in surprise and the two rolled grappling and giggling on the mat.

 Beta motioned for Sans to follow. Sans glanced warily at Papyrus.

 “It’ll just be a few minutes, I promise,” Beta winked. Sans sighed giving in and followed his friend out of the activity room and down the hall to Beta and Undyne’s cell. The room was quaint and simple, like Sans’s and Papyrus’s. It sported one bed, a single sheet and a pillow. Much like Sans’s and Papyrus’s. Sans wondered what was going to happen once Undyne and Papyrus got too big to share a bed with their siblings?

 Would the doctors give them a second bed? Probably not. Sans and Beta would end up on the floor, Sans just knew it.

 “Really impressive buddy,” Sans said sarcastically looking around the room. “Don’t think I’ve ever seen something this cool.”  Beta rolled his eyes scoffing at Sans.

 “Don’t be a smart ass!” Beta closed the door behind Sans and led him over to the bed his eye flickering to the camera.

 Beta turned away from the camera placing a finger to his lips before he winked. A blue spear hovered out of view of the camera, tapping it gently.

 “I can loop it for about five minutes. The sound’s been busted for ages and they’re too lazy to fix it My magic’ll make it look like we’re talking. Okay, so,” Beta pulled the metal bed, revealing a hole beneath it. Sans stared blinking stupidly.

 “Wait. Seriously? You dug a hole?” Sans hissed.

 “If I have live with being gifted with amazing manipulation magic where I can hack into electronics, do you really think I’d let a couple of metal walls stop me from accessing their computers to toy with?” Beta demanded.

 “. . . you dug a hole to the computer lab?” Sans asked.

 “Even better. I dug a hole to Experimentation Room 1-D.” Beta grinned nastily.

 “That’s where the determination extractor is. . .” Sans blinked in surprise.

 “Yep. Come on. You gotta see what I’ve been doing in there, it’s awesome! Plus, we only have three minutes left so get your bony ass moving.”

 Sans sighed, watching Beta jump down the hole. This was going to end badly, Sans just knew it.

**Notes for the Chapter:**

> Edit: Updates randomly 
> 
> This is technically a prequel to my other fanfiction Saving Papyrus, but you don't need to read it to understand any of this, because, well, it's a prequel. ¯\\_(ツ)_/¯
> 
> \--But Chaos why are you posting a third 'weekly' story when you already have two other stories that update weekly?
> 
> BECAUSE I'VE LOST ALL CONTROL OF MY LIFE.


	2. Talk sense

**Summary for the Chapter:**

> Beta shows Sans what he's been up to and some cute fluff happens.

**Notes for the Chapter:**

> Ahh! I can't believe this already has so many kudos and bookmarks and comments that's pretty much a record for me as far as first chapters go! Thanks so much!!!
> 
> this chapter is mostly world building and character introductions/ build up.

_That if you talk enough sense, then you'll lose your mind_

 ***

Sans

 “The fuck am I looking at?” Sans demanded. He had crawled through the tunnel that Beta had carved through yards of concrete and steel, all the way to Experimentation room 1-D. Beta had shoved a desk away as they had emerged. The desk had been hiding the entrance to the tunnel the two had crawled out of and Sans was standing in front of a large and imposing machine.

 “That’s the determination extractor,” Beta grinned nodding at the large animal like skull shaped metallic monstrosity. Sans shivered. It looked familiar, though Sans was certain he had never seen it. In a way, it reminded him of his blasters. It hovered above a square hole held with wide metallic wires that winded down from the ceiling. Around the square hole and DT extractor were rows of computers.

 Sans had never personally seen the determination extractor until now, but he knew of its existence. He well remembered the small little red haired human girl the scientists had hauled in. The one with the tutu. He remembered the child’s screams, How Dr. Gaster had forbade him from entering the room, and he remembered the blue integrity soul Dr. Gaster walked out with to deliver to the King.

 “Fucking creepy right? Come on we have like a minute and a half left before we have to haul our asses back to my room,” Beta huffed pulling Sans to the edge of the hole. Sans looked down and swallowed. It seemed to go down forever. Why was it even there? Sans wasn’t sure he wanted to know.

 “Okay, so. Osa’s been bitching about the DT experiments,” Beta summoned a cyan spear before stabbing it into the left most ‘wire’ that held the DT extractor.

 “Holy shit what are you doing!?”  
  
“Relax. I’ve been doing this for weeks,” Beta huffed rolling his eyes. The spear shook, violently so, and a string of numbers and codes hovered in front of Beta.

 “What. . . is that?” Sans demanded.

 “The machine’s code. Well, okay, this is my magic manifesting the machine’s code. I’ve been making subtle changes,” Beta grinned. Sans frowned at the masses of 0’s and 1’s in front of him as if displayed on a screen, except in thin air, the same cyan color as Beta’s magic.

 “Can you read it?” Beta asked.

 “A little,” Sans admitted. Dr. Gaster has been teaching him to read code but this was more complex than Sans had dealt with so far. Beta began rearranging some of the 1s and 0’s his hands moving quickly.

 “If I alter it too much they’ll notice, but, little by little, like this, they won’t know what the fuck is wrong with it, or why it won’t work,” Beta grinned before glancing at his watch.

 “Fuck. time to go,” Beta waved his hand the code disappearing and his spear. Beta quickly ushered Sans back into the tunnel and followed, pulling the desk back to hide the tunnel. The two crawled back in silence, back to Beta and Undyne’s cell. Beta looked at the camera warily, which still had one of his spears touching it. Beta dragged the bed back over the hole.

 “Phew, with seconds to spare,” Beta gave a lazy grin as his spear faded.

 “Okay, seriously, what the fuck?” Sans demanded taking a seat on Beta’s bed crossing his arms. “Your messing with the DT extractor? Are you suicidal?”

 “I’ve been doing it for weeks and no one’s noticed,” Beta scoffed waving Sans off.

 “But why?” Sans demanded.

“Well. I’m kind of bored,” Beta admitted. “My magic is strong in electronic manipulation and there having me focus on my ‘feelings’ and shit for the SOUL experiment. I don’t want to sit and talk about feelings, that’s bullshit. I want to hack, I want to get my hands dirty. I want to take apart a computer and see if I can put it back together,” Beta said passionately punching his fist into his hand.

 “You dug a tunnel to Experimentation room 1-D, to hack into the DT extractor _because you’re_ _bored_?” Sans demanded.

 “Well. . . yeah,” Beta shrugged. “AND like I said, fucking Osa’s been bitching about the DT experiments. As in you. She wants other test subjects to start since you're almost done. She wants to put me in, and Undyne, and...” Beta said, and he paused. “And Papyrus.”

 “I know.” Sans all but growled. “But Papyrus and Undyne are too young, even Dr. Gaster said that,” Sans said frowning. “I don’t want _anyone_ to have to go through it,” Sans said clenching his hands into fists. The DT injections were incredibly painful. Sans didn’t want Beta or Undyne to have to go through it, and especially not Papyrus. Sans was not going to let that happen to Papyrus, not ever.

 “I’ll get pulled in,” Beta said shifting slightly with a frown. “I know I will. I’m not giving ‘results’ with the SOUL project. Once you’re done they’re going to want a new test subject for the DT injections. It’s going to be me,” Beta said with a grim look. Sans swallowed. Beta was probably right.

 “‘m sorry,” Sans said averting his eyes.

 “That’s why I’ve been sabotaging the DT extractor. I don’t know how much DT they have on hand, but they’ll run out. They’ll need to harvest more,” Beta said, and he grinned. “And the next time they try to harvest DT, well, it aint gonna work,” Beta smiled wider showing off his sharp pointed teeth. Sans shook his head with a soft chuckle.

 “You’re insane buddy. If they catch you-”

 “They aint gonna,” Beta waved Sans off.

 “Just be careful,” Sans groaned into his palms. “You’re literally my only friend in this dump I really don’t want to see you get hurt.”

 

***

Dr. Gaster

 “The fuck am I looking at?” Gaster demanded, frowning down at the small child in front of him. It was his smoke break. Gaster had literally one rule when it came to breaks. No work during said breaks. Particularly smoke breaks. Gaster sighed taking a long drag of the cig, trails of smoke leaving his sockets.

 Dr. Alphys flinched in front of him, shifting slightly. Gaster usually was more professional around his colleagues but it was his fucking smoke break.

 “Sh-She’s a fire elemental,” Alphys gestured to the small child. Said child squeaked, clinging to Dr. Alphys’s leg. The child was small, with Blue flames. Some of them curled down from her head in curls with purple tips, making it look like ‘hair’.

 “K-King Asgore demanded we st-study her. Elementals are rare. You know how many we lost in the war,” Alphys shifted slightly. Gaster sighed. As far as he knew there was only _two_ humanoid fire elementals left; Grillby and his partner Haru. If you didn’t count the midget pyromancer fuckers, which, Dr. Gaster didn’t.

 “I’m sure her parents were oh so pleased by King Asgore’s decision to relieve them of their daughter?” Gaster spat sarcastically taking another drag of the cigarette. Alphys shifted slightly.

 “Uh. I-I uh, no. Um. I th-think the mother died during the extraction process. The father’s being uh detained.” Alphys squirmed.

 Of course.

 “Because you know if the king had left their happy little family alone, maybe they’d have had more children.” Gaster huffed. So many monster races were on the brink of extinction. Skeletons, Elementals, and Wraiths to name a few.

 “What’s your name?” Gaster sighed down at the small flame girl.

“F-Fuku,” The girl whispered. Gaster sighed. So, it _was_ Grillby’s daughter. Of fucking course. Gaster didn’t have many friends, but Grillby was one of them. Apparently not for long.

 “And the King demanded we use her as a test subject?” Gaster put his cigarette out.

 “I have the official r-report,” Alphys shifted nervously.

 “I want her under your project Dr. Alphys,” Gaster said. Alphys’s blinked looking surprised.

 “Y-yes sir!” Alphys said. “I- I won't let you down,” Alphys added. Gaster bit back the response that Alphys had _already_ let him down, several times a day in fact, and instead he waved the lizard monster off. Gaster watched with narrowed sockets as Alphys quickly carried the upset child away, inside the lab. Gaster gave a forlorn look at his half-used cigarette and walked back into the laboratory, praying to the angel that Osa wouldn’t happen to cross paths with him and made his way into his office.

 Gaster pulled out Papyrus’s file and turned on his computer observing the cameras. Nothing unusual. B-4 and Sans were chatting in B-4’s cell. U-6 and Papyrus were playing in the activity room. Gaster huffed flipping through his paperwork.

 What was he going to do with Papyrus? There was a _lot_ of potential there. Papyrus had high HP for his age HP and adequate stamina. Far better than what Sans possessed. Gaster could do experiments on Papyrus that would be unsafe for Sans. the possibilities were intriguing.

 Besides, Papyrus would be a much more efficient weapon against a human than Sans. Not that Sans was a weak weapon. Gaster had insured Sans’s ATK made up for Sans’s lack of HP and stamina. Sans’s magic was unusually high without Gaster’s meddling, so Gaster had given it a little push and with the blaster, Sans was truly a force to be reckoned with. If only the determination would have some kind of effect.

Gaster glanced curiously at the screen as Papyrus slid down a rope and leapt on the fish girls’ back.  Gaster had already begun crafting Papyrus’s blaster, and Gaster was proud of his work. If he reared Papyrus correctly, he would be a deadly force with no equal. Not even Sans would outdo him. Papyrus could be the ultimate warrior and weapon against the humans.

  U-6 seemed to have a spirit Papyrus lacked when it came to fighting however. Even at this young age. Gaster gazed at the screen as the small fish girl lunged at the skeleton playfully and chased him around the jungle gym. Papyrus was a pacifist. He was sweet. Today was the first time he had attacked someone, and it had been Gaster. Gaster would have to push the young boy, to keep Papyrus on the offense. The fight that had blossomed with in Papyrus needed to grow and be groomed.

 Papyrus could be taught how to fight, even if Papyrus didn’t _want_ to fight. He was strong, healthy and he could be molded. Determination might have a greater effect on Papyrus than Sans. Sans had to be given such small doses due to his HP and his results were unsatisfying. Papyrus could certainly handle more without the risk of melting. Still, five was too young for Determination injections. Gaster hadn’t started Sans until he was eight. So what project could Gaster put Papyrus into in the meantime? Papyrus got along with Undyne. Perhaps he could enlist them both into the ENHANCEMENT project?

 A sharp shriek distracted Gaster from his musings and his crimson eyelights flickered to the screen where Papyrus was now curled up in the fetal position. U-6 was standing over him her eyes wide, and Papyrus’s bones began to clack as the boy shook. Something strange surged through the doctor at the sight.

 An irrational urge to run to the boy and scoop him in his arms panged through Gaster’s soul. Another urge arose, a want to make whoever had hurt his ~~child~~ experiment pay. In this case that would be the small fish girl. Gaster gripped the table hard taking a calming breath. This was irrational. Children would be children. There was no reason to take ‘revenge’ on U6 or to coddle Papyrus. There was no reason Gaster should be feeling this way. It had no benefit. It was just some primal animal instinct in the depths of his magic to protect what his magic identified as ‘his’. Nothing more.

 Gaster took another calming breath before pressing the button for the intercom to B-4’s cell.

 “S-4! Go check on P-7. I don’t have time to deal with his sniveling.” Gaster snapped. He saw Sans bristle on the camera and Sans turned to scowl at it before holding up a lone middle finger. Gaster scowled un-amused by his eldest’s antics. Gaster watched the two teenagers quickly walk down the hall towards the activity room. Gaster sighed pressing his palms against his face. Maybe Osa was right. Maybe ~~his~~ the boys were making him weak.

 ***

Papyrus

 “Ow!” Papyrus sulked giving Undyne an accusing look.

 “I’m sorry!” Undyne said for a third time, mournfully. “I didn’t mean to!” Papyrus closed his eyes with a whimper. He was a big boy now. That’s what Sans said. He had to be strong. He wouldn’t cry. Big boys don't cry, right? Sans never cried!

 “What happened?” Sans’s rough voice demanded. Papyrus looked up with round sockets as Sans ran in, Beta right behind him.

 “Sans!” Papyrus reached for his brother and hissed at the pain it caused.

 “The fuck!?” Sans demanded his eyelights going out as Sans stared at Papyrus’s leg. Papyrus whimpered staring down at it as well. It wasn’t supposed to bend that way! It hurt!

 “Stars, Paps!” Sans knelt next to Papyrus and pulled the smaller skeleton gently into his arms.

“Hurts.” Papyrus whimpered, and he turned to bury his face into his brother’s black and red striped shirt.

 “Hey. Shh. It’s okay, I got’cha,” Sans said soothingly.

 “Fix him!” Undyne demanded.

 “Undyne shush,” Beta said tugging his sister gently, giving the skeleton brothers some room.

 “Hey, Paps, why are skeletons so calm?” Sans asked, gently gripping the dislocated bone.

 “Ow- don’t touch it Sans!” Papyrus shrieked.

 “Because nothing gets under their skin,” Sans grinned. Papyrus blinked before he began giggling.

 “What did the skeleton chef say when he served a meal?” Sans asked.

 “I don’t know,” Papyrus gave Sans a puzzled look.

 “Bone appetite!” Sans said. Papyrus giggled again.

 “Stop! Those are so stupid,” Papyrus said with a snort.

 “Nah, you just don’t have the guts for them,” Sans winked. Papyrus giggled and grinned. “Paps, hey. I need to pop the bone back into place, yeah?” Sans said his smile tilting downwards.

 “No!” Papyrus squeaked trying to pull away from his brother. That was going to hurt!

 “Hey! Hey stop. Papyrus, relax!”

 “Don’t touch it!” Papyrus whined, staring up at his brother with wide eyelights.  Sans sighed, looking away.

 “Why didn’t the skeleton dance at the Halloween party?” Sans asked. Papyrus paused looking thoughtful. Papyrus wasn’t sure- Sans firmly popped the bone back into place.

 “OW!” Papyrus screamed. He couldn’t believe Sans had tricked him!

 “He had no body to dance with,” Sans said with a wink.

 “THAT HURTED.” Papyrus scowled, crossing his arms glaring up at his older brother.  

 “But it feels better now, right?” Sans asked. Papyrus huffed but nodded.  “What happened?” Sans asked light green magic flowing from his palm soothing the small ache that had lingered in Papyrus’s femur. Papyrus leaned into his brother’s arms watching the healing magic curiously. How did Sans do that?

 “We was playin’ and. . . I tripped,” Papyrus said looking way. He didn’t like lying to Sans, but he didn’t want Undyne to get in trouble.

 “I tackled him offa the jungle gym,” Undyne mumbled. Papyrus glanced at her with wide sockets. He was trying to keep her safe! Why would she do that!? Sans would tell Gaster and she’d get in trouble.

 “Don’t tell on her Sans!” Papyrus said quickly. Sans blinked looking confused.

 “I’m not gonna snitch. Geeze. Listen ya little heathen,” Sans scowled at Undyne. “Ya need to be more careful with my brother, capiche?” Undyne nodded quickly. Sans glanced back down at Papyrus. “Feeling any better?”

 “Yeah,” Papyrus said, clinging to his brother tightly. Sans smiled gently.

 “Yo, sis, this is how you properly tackle someone,” Beta said. Undyne’s eyes widened.

“No, no, no, no!” She screamed and ran, and Beta spear tackled the smaller fish, landing on the mat with his sister in his arms and began tickling her. She shrieked with laughter her face turning red.

 “Huh,” Sans said.

 “...Sans no!” Papyrus gasped realizing he was trapped in his brother’s arms.

 “Do you think skeletons are ticklish?”  
  
“No- don’t! Hahaha- stop!” Papyrus yelled as Sans’s fingers expertly tickled, tearing giggles from the smaller skeleton.

 ***

Dr. Osa

 This was ridiculous. Why was Osa doing lab assistant work? She was a scientist for stars sake. Second only to Dr. Gaster himself! Osa growled carrying the orange inverted heart in its glass case to Experiment room 1-D. Of course, all the lab assistants and techs were busy with the training seminar that had been going on, and Dr. Alphys was integrating some new brat into her project.

 Osa huffed pulling the human soul out of its casing and placing it in the metallic restraints in front of the DT extractor. Osa stepped aside, turning on the machine. Red liquid began to leak from the ‘eyes’ of the skull shaped device. It’s ‘jaw’ opened wide and a harsh whining sound filled the room.

 A white beam of light shot from the DT extractor into the soul. Red liquid was extracted from the soul through the beam towards the machine. Osa sighed impatiently. The machine stuttered, and a metallic groan rang throughout the room. Osa frowned. That was unusual.

 The beam of light stuttered and disappeared.

 “What? No!” Osa said and she cursed as the long string of determination that had still been within the beam fell into the depths below. “What the hell!?” Osa hissed. The machine gave another metallic groan, red determination flowing from its ‘eyes’ and spilling into the giant hole beneath.

 “Fuck!” Osa ran and slammed the off switch. Unbelievable. Impossible. The machine was malfunctioning? It had never done this before.

 Its design had been flawless. Like the CORE. Designed by Dr. Gaster. It was unusual for his inventions to malfunction. Osa smirked. Well maybe she could rub that in Wingdings face? Osa’s smirk widened, not that anyone would see as her hood hid her facial features as she made her way to Dr. Gaster’s office. She pushed the door open without knocking.

 The skeleton scoffed, his sockets narrowing at her, a pen in his hand. He was scrawling equations on some scrap paper.

 “Osa. We’ve talked about this,” Gaster sighed his red eyelights meeting her gaze. “Knock on the fucking door before you enter my office.”

 Osa cocked her head to the side and knocked on the door. Gaster slowly breathed out giving her an impatient stare.

 “You’re not funny.” Gaster said.

 “I don’t know Wingdings,” Osa drawled stepping forward. “You might be onto something. I think I’m more aDOORable than funny,” Osa shrugged. Gaster groaned.

 “I hate your puns. You _know_ that.” Gaster spat. Osa tapped her gaunt fingers against his desk. "I swear you used to tell puns to Sans just to annoy me."

"S-4's appreciation of puns is the only reason I tolerate his existance," Osa drawled.

 “What do you want?” Gaster sighed. Osa smiled.

 “Your machine is broken~” Osa drawled, unable to keep her delight from her voice. Gaster gave her an unimpressed look.

 “Don’t blame the machine when the user is at fault Osa,” Gaster said raising a single brow bone. Osa scoffed.

 “I didn’t make any errors! _Your_ machine is _broken_.” Osa crossed her arms.

 “I highly doubt that. But, fine, I’ll play. Which machine is broken?” Gaster said putting his pen down and staring up at her boredly.

 “The DT extractor. It’s malfunctioning. It stopped extracting DT.” Osa said.

 “What?” Gaster demanded his ruby eyelights shrinking. “Impossible!”

 “Guess you’re losing your touch, huh~?” Osa smirked.

 “Shut up. You clearly did something wrong,” Gaster huffed. Osa scowled.

 “I did not!” Osa scoffed.

 “A hundred gold says you weren’t using it right,” Gaster said. Osa growled.

 “You’re on.”

**Notes for the Chapter:**

> Sans and Gaster saying the same line was on purpose ;) They're a lot more alike than either would care to admit.
> 
> Gaster has quite the foul language but keeps it professional unless he's on a smoke break, with the skeleton brothers, or with Dr. Osa.
> 
> Next chapter Gaster becomes very displeased with what happened to his machine. 
> 
> It was totally Osa's fault, really!


	3. Focal point

**Summary for the Chapter:**

> Some things are learned about everyone's least favorite scientist and Gaster has a special task for Beta and Sans.

**Notes for the Chapter:**

> *cough*
> 
> I realize it's a little past Thursday >.> MY BAD! 
> 
> Papyrus and Undyne are so freakin cute and sweet man, it hurts my teeth writing them. The kids need to be cute and adorable while it lasts!

  _And I'll use you as focal point_

 ***

W.D. Gaster

 

“What the hell did you do to my machine!?” Gaster demanded, frowning at the DT extractor as it shook and trembled from a failed attempt to extract DT from the orange soul in front of him.

“Nothing!” Dr. Osa snapped her voice raising. “It was like this when I came in. Maybe there is a flaw in your design, because _your_ machine is malfunctioning!

“My machines are _flawless_ ,” Gaster huffed summoning his magic and two giant skeletal hands manifested into being, a red aura around them. Each giant hand, matched his hands, sporting a perfect circular hole in each palm. The hands pulled at the thick cable wirings that pierced into the ceiling, lowering the machine and unplugging it, before Gaster gripped the metal casing on the side, sliding it off with his bare hands and examining the mechanisms within.

Gaster sighed. There was no immediate obvious error. No stuck cogs, no wires amiss, and no tears or breaks. Everything appeared to be in order. It was going to take time, time Dr. Gaster didn’t have, to discover what was causing the machine to malfunction. Gaster growled under his breath with impatience. He had other tasks that needed his immediate attention.

“This is going to take time. We will have to hold off on further DT extraction,” Gaster huffed his magical extra hands carrying over a box of tools to him as he delved into the innards of the machine.

“How long?” Osa demanded.

“It will be fixed when it is fixed,” Gaster scowled.

“Do you have enough DT for S-4’s next injection? If the injection is late, theoretically it could set the project back. Especially when the project is so close to completion,” Osa said with a click of disapproval. Gaster paused to look over his shoulder and glare at Dr. Osa.

“I am _quite_ aware of the risks,” Gaster said coldly, using a wrench to unfasten a bolt in front of him to peel back another layer of metal. Osa sighed loudly.

“What did you need DT for anyway?” Dr. Gaster asked raising a brow bone his colleague. Osa stiffened. As far as Gaster knew, Osa didn't need DT for any of her current experiments or test subjects.

“I had some spare time and thought I’d refill our reserves,” Osa said with a noncommittal shrug.

“Bullshit!” Gaster snapped slamming the machines casing shut and casting his crimson eyelights on her. He noted the way the other scientist flinched. Good.

"Well, I _might_ have been planning on studying DT’s connection to clairvoyance,” Osa admitted. “That last human child we caught, they seemed to know things were going to happen before they did, as if they could see into the future. It has me curious,” Osa tapped her slender fingers against the metal contraption holding the soul in question.

 “Hm,” Gaster stepped forward, his left eyelight flickered out of existence leaving an empty socket. The remaining eyelight was enveloped with blood red fire. Osa took a cautious step back.

“Next time,” Gaster said softly, taking another step forward. Osa took a second step back, her back hitting the wall.

“Dr. Gaster-”

“You should get your superior’s permission,” Gaster’s hand shot out wrapping around her soft vulnerable throat within the hood’s inky darkness. “Don’t you think?” He squeezed, hard.  
  
Osa gagged and her fingers clawed at the boned fist around her throat uselessly. Gaster’s mouth twitched into a grin and he squeezed harder.

Osa’s fingers lit in icy wisps and a blue fireball sailed past his head harmlessly. Gaster pulled the woman closer staring into the blue pits within the hood until they dimmed into icy blue irises.  Gaster released her and the woman gasped for air, coughing.

“ _You_ -”

“Careful Dr. Osa. I wouldn’t want you to disrespect your superiors.” Gaster drawled. Osa growled, low within her abused throat and her palm crashed across his cheekbone. Gaster chuckled softly and grabbed her bony wrists pulling her against him.

“No!” Osa hissed, startled, and Gaster pulled her hood back, his eyelights scanning over the pools of raven locks cascading over thin shoulders. Osa’s cheeks puffed angrily and her ice blue eyes narrowed.

Gaster gripped her hair, hard, pulling her head back and he slid a crimson tongue along her neck.

“I have a task for you,” Gaster growled lowly, in her ear.

“You _pompous asshole_ -” Osa snarled and Gaster’s sharp fangs grazed the warm flesh of her throat.

“You’ll be a _good human_ , won’t you?” Osa shivered against Gaster, goosebumps raising on her pale blue flesh.

“How _dare_ you, I’m **not** a-”

“I need you to teleport me into the dungeons in Hotland. I have an old friend to visit. I’ll make it worth your while,” Gaster drawled with a grin and he bit down hard.

***

Sans

“Sans?” Papyrus looked up at his big brother from the plate of food in front of him.

"Yeah, bro?” Sans squeezed the bottle of mustard in front of him over his food and chuckled as his brother made a face. The food tasted like shit here, but he loved mustard, and mustard made everything taste better.

The ‘mess hall’ for lack of a better term was a fairly large room with rows of tables. The test subjects all late at the same time, all watched by a handful of lab techs. Sans cast a glance at Osa’s batch of test subjects at the table across from them. Poor bastards. Osa only had three specifically assigned to her, as she assisted with Undyne, Beta, Sans and Papyrus and some of Alphys’s test subjects. The three quiet monster children directly under her care always seemed to shamble about and were eerily silent.

“Am I going to start getting DT injections?” Papyrus asked softly with a frown, pushing his food around with his fork.

“Hell no!” Sans growled.

“But Osa said-”

“You heard Gaster, you’re too young,” Sans stabbed his food with his fork angrily.

“What about when I is bigger?” Papyrus asked softly.

“I ain’t ever gonna let that happen to ya bro, I promise,” Sans said firmly. Papyrus nodded quickly and smiled.

“Who’s the newbie?” Beta said taking a seat next to Sans, looking over to the table on the other side of them, where Alphys’s lucky test subjects sat. Sans’s eyelights fell on a small blue elemental girl, looking to be made entirely of fire. She was sitting off to the side looking terrified, her food untouched.

“No idea. Another orphan maybe?” Sans shrugged.

“Sure are a lot of orphans, don’t ya think? What do you think it's like out there? Outside the lab?” Beta huffed.

“How would I know? I’ve never seen it, don’t you remember?” Sans shrugged. Beta hadn’t been dropped off until he was four. Though his sister had been left at the lab soon after her birth.

“I don’t remember much honestly,” Beta frowned. “I remember water, lots of water. And waterfalls? Like in the books,” Beta shrugged.

“Ugh! Books are boring!” Undyne huffed hopping in the seat next to Papyrus.

“I like books,” Papyrus said with a smile.

“You can't read,” Undyne scoffed.

“Sans reads to me! And he’s teaching me!” Papyrus huffed.

“Nerd!” Undyne teased with a grin. Papyrus stuck an orange tongue out at Undyne and she pulled her eyelid down making a face back at him.

“You two,” a vulkin lab assistant called over gesturing to Sans and Beta. Dr. Gaster wants you two to report to room 4-E after dinner,” The vulkin said curly.

“What for!?” Beta scowled.

“Yeah, come on, the doc has had us doing shit all day,” Sans scoffed.

“What’s shit?” Undyne demanded.

“What Sans is in, deep,” Beta growled. Sans gave his friend a nervous look.

“Aw come on, it slipped,” Sans shrugged with a nervous wink.

“Don’t be late. Room 4-E.” The vulkin snapped before walking off.

“Ugh. What do you think this is about?” Beta scowled watching the Vulkin go.

“Some stupid bullshit tests probably,” Sans said looking thoughtful. “But the doc never usually runs experiments after five,” Sans wrung his hands together nervously. Had Dr. Gaster realized Beta had tampered with the determination extractor? Were they in trouble? Sans’s soul pulsed anxiously.

“Well while you two are doing that, Papyrus and I have shit to do,” Undyne said copying Sans’s words. Sans sighed, and Beta scowled at Sans. Sans felt sweat bead at the top of his skull.

“Uh? Heh?”

“ ‘Dyne, don’t say that, that’s a bad word,” Beta sighed.

“But Sans said it,” Undyne scoffed.

“Sans can,” Sans said taking a swig of mustard.

“Ew,” Papyrus made a face at him and Sans grinned.

“How come Sans can say stuff and I can’t!?” Undyne demanded.

“Because Sans is bigger than you squirt,” Sans said. Undyne’s yellow eyelights narrowed before she growled and threw her spoon at Sans’s forehead. Sans blinked as the spoon bounced off his skull and onto the table. Beta burst into laughter and Papyrus snorted. Sans shook his head. _This little shit!_

The bell rang, signaling it was time for the test subjects to leave the mess hall back to the west wing, except for Sans and Beta, who apparently were being summoned to experiment room four.

 ***

W.D. Gaster

“You’re an insufferable bastard, you know that?” Osa growled softly, readjusting her cloak.  Gaster grinned against his cigarette shrugging his shoulders. Osa smiled, despite herself, before sliding her hood back on, hiding her human looking features, and the bite mark claiming her neck. Cold blue irises, raven black hair, her human face, and the blush on her cheeks all disappeared in a shroud of darkness as the hood descended.

“The dungeons in Hotland?” Osa questioned her head cocking to the side curiously. “What on earth kind of business do you have there?” Osa huffed. Gaster flicked the butt of his cigarette to the side, adjusting his suit and lab coat, pressing out the wrinkles.  

“Curiosity killed the cat, Osa.” Gaster said looping an arm around her shoulders.

“You gotta be _kitten_ me,” She said a smirk in her voice. Gaster grunted in annoyance at the pun. “If you want to keep those mutilated hands of yours, you’ll remove them from my person at once,” Osa warned, and ice like magic began sparking between her fingertips.

“That’s not what you said five minutes ago,” Gaster drawled under his breath, squeezing her shoulder. Osa scoffed and the world around them faded into darkness. Gaster’s red eyelights observed the void curiously as it closed in around them, invading and ominous and then it was gone, they were in King Asgore’s dungeon, the cells expanding in front of them seemingly never ending. Groans and whimpers cried out from individual cells.

Osa shrugged his hand off her shoulder and he motioned for her to follow, trailing down the long hall silently, peering into each cell as he searched for the one he had come here for. After a few moments of silent investigation Gaster stopped in front of the cell holding the purple fire elemental.

Grillby’s HP was deplorable, under 10. The guard’s way of keeping prisoners from breaking out. No food, low HP, both made for weak and cooperative prisoners. Not that anyone stayed a prisoner for long.

“Hello old friend,” Gaster drawled gripping the bars in front of him. Grillby looked up, the yellow pits for eyes widening in surprise.

"Gaster?" Grillby's voice crackled like a campfire. "You smell like that mage bitch," Grillby scoffed. Osa growled from behind Gaster and Grillby's jack-o'-lantern like mouth twitched into a half grin.

“Her stench does tend to linger like garbage, doesn't it?” Gaster grinned. Gaster ducked as a wave of flames sailed at where his head had been. The flames crashed into the bars of Grillby’s cell, melting several bars into a silver puddle.

“Temper, temper,” Gaster scolded. “But I must thank you Dr. Osa, for breaking the cell open for me.”

“I hate you,” Osa growled.

“Oh, I know,” Gaster stepped back and Grillby stood up from the bench he had been seated on. Grillby stepped through the missing bars, squeezing from his cell.

“If Asgore finds out about this, there will be hell to pay,” Grillby said quietly.

“If you hadn’t set twenty of his guard on fire, maybe my job would have been easier,” Gaster scoffed. Grillby gave a grimace.

“Haru. My mate. They dusted my Haru,” Grillby growled, his flames growing, his frame shaking. “They _deserved_ it.”

“I'm sorry,” Gaster said softly. Grillby’s flames dimmed some, and the fire elemental sighed.

“Fuku. My daughter. Where is she?” Grillby demanded.

“Safe.” Gaster said shortly. Grillby's flames flickered.

“That lab is anything but safe! You’ll bring her to me _right now_ before I find out what heat bones melt at!” Grillby snarled. Gaster rolled his eyelights at the threat giving an impatient sigh.

“Oh, please do,” Osa said with a chuckle.

“Seriously, why did you have to bring the mage?” Grillby demanded.

“She missed you,” Gaster shrugged.

“I hate you _both.”_ Osa snapped.

“It's under the king’s orders that we study Fuku. My hands are tied. If you and your daughter go missing around the same time I will be suspected. I have her with my most merciful scientist. Fuku is safe. I ask that you give me three years,” Gaster said his eyelights scanning the purple fire elemental over thoughtfully.

“Three years!?” Grillby hissed.

“Yes. Wait three years, and there will be an ‘unfortunate lab accident’. Then I’ll return her to you, I’ll have gathered useful data, and Asgore shouldn’t go digging into it.” Gaster shrugged.

“What am I supposed to do for three years? Where am I supposed to go! I’ve lost _everything_. I can't go home; the guard will be looking for me! My restaurant, my mate my daughter, everything!” Grillby said clenching his fists.

“Go to Snowdin. The guard is scarce there. No one will know who you are. It’s not as heavily populated, and the town is in desperate need of a restaurant, the town is downright dreary. Start over there. You know where my home is, I’m almost never there. Use it for a while and build your life back up. By the time I return your daughter to you, you should have the means to actually care for her,” Gaster lit a cigarette taking a slow hit. Grillby sighed.

“I. . . thank you, old friend,” Grillby said softly.

“What are friends for?”

 ***

Sans

 

“It’s been over an hour,” Sans groaned with a frown, staring at Beta. Beta shrugged, sitting on the floor his hands deep inside the innards of 4-E’s former computer. “Maybe the vulkin was confused? Should we go?” Sans suggested.

“You know that if Dr. Gaster comes in this room expecting us and we’re not here there’ll be hell to pay,” Beta said, throwing a piece of machinery over his shoulder.

“But Gaster’s never this late,” Sans groaned.

“Maybe he fell asleep? He falls asleep a lot,” Beta shrugged, stabbing one of the wires with his cyan spear.

“What exactly are you doing?” Sans asked curiously.

“I’m not sure. I’m just kinda exploring,” Beta grinned at him.

“I really don’t think anyone’s going to appreciate that,” Sans said with a smirk.

“Good,” Beta said, pulling out wires and tossing it to the side. Sans shook his head. The door slammed open and Gaster walked in pulling an alligator  monster and a purple cat monster behind him with blue gravity magic.

“Please! Let us go!” the alligator whimpered.

“LIke, we are sorry!” the cat monster cried.

“Totally sorry!” The alligator woman added quickly.

“Silence,” Gaster snapped at them, rolling his crimson eyelights. He pushed the two monsters to the floor, both their souls glowing bright blue from his magic. Gaster’s eyelights flickered over Sans, then Beta who sat nervously his hands still inside the casing of the computer in front of him.

“B-4, what exactly do you think you’re doing?” Gaster demanded.

“Uh. Fixing it?” Beta said and cleared his throat. “Sir?”

Gaster sighed pinching above his nasal passage before he growled in wingdings.

“Uh? What?” Beta frowned, quickly stepping away from the computer.

“He called you a little shit, and some other stuff.” Sans said cheerfully. Gaster shot Sans an annoyed look.

“B-4, we will discuss your. . . “fixing” of the computer later. I have a task for you two. You’re both teenagers now, so it’s about time you both gained some LOVE,” Gaster gestured to the two monsters he held by gravity. He waved his arm and the two girls shrieked as they slammed against the nearby wall. “Kill them.”

“W-what!?” Sans demanded his eyelights shrinking to pinpricks.

“O,M,G! Like no! Don’t do that!” The purple cat monster gasped her yellow eyes widening.

“Like, I’m not ready to die!” The blonde alligator agreed.

“I ain't killing anyone!” Beta scoffed crossing his arms. Gaster snorted.

“It’s amusing that you think you have a choice,” Gaster said. “You both need LOVE. It will increase your stats and you’ll be able to defend yourselves far better. Frankly, I should have made you gain LOVE long before today. Now, kill them,” Gaster ordered.

“But-I can't just kill an innocent monster,” Beta said clenching his fists.

“They are _hardly_ innocent.” Gaster’s left socket went blank, the right flickered blue and yellow as he stared at them. Judging them. His eyelights returned to normal. It’s kill or be killed. Had the positions been reversed they wouldn’t think twice about killing you. Kill one of them, now B-4. Sans, you kill the other.”

“No!” Sans said. He wasn’t killing _anyone_ , innocent monster or not. He refused.  Papyrus would never look at him the same if he did. Hell, he wouldn’t look at himself the same if he did. Gaster blinked looking surprised by Sans’s blatant disobedience.

Sans scowled at the floor. He wouldn’t do it. He refused. He didn’t care what Gaster wanted. Sans wasn’t going to kill anyone unless he had no other options. Unless his or Papyrus’s life was in danger, Sans wasn’t going to hurt anyone.

Beta was glaring at the floor his fists shaking. Gaster sighed in annoyance.

“Do _not_ , make me motivate you two.” Gaster growled.

“I don’t care!” Beta yelled. “I don’t care what you do, you can’t make me kill an innocent monster, I won't! I won't do it!”

Gaster sighed and his eyelights flickered to Sans. “And you feel the same way?” Gaster asked.

“Yeah,” Sans said softly, looking down. Gaster must be pissed at Sans. Sans didn’t know why that bothered him. Sans didn’t know why he tried so hard to gain the scientist’s approval.

“Very well.” Gaster’s release on the two girls lifted and with squeaks of surprise the two girls dropped to the ground.

“O, M, G! Like, thank you little boys!” The purple cat gasped.

“Totally, you’re life savers!” The alligator said.

Sans blinked in surprise. Gaster was letting them go? Just like that? Was this some kind of test on their morals or something? Had they passed? Gaster looked put out, and he crossed his arms before leaning his back against the closed door.

“Girls. If you two want to get out of here alive, you’ll kill them,” Gaster said his voice monotone. Sans’s eyelights went out. _What?_

“Like, . . .okay,” The alligator grinned nastily, summoning a long red sword of her magic into her hand. Something pulsed from within her, like a punch to Sans’s gut.

**RAGE/KILL**

Sans blinked from the awful feeling emitting from the girl. No, not just a feeling, it was her _intent._ That was killing intent. It felt _awful._ It felt wrong.

“Bratty! No! They’re obviously still in stripes!” The purple cat gasped.

“Catty! It’s us or them. Who’s gonna miss two lil’ brats anyway? The streets are crawling with them.” Bratty pouted. Catty paused looking unsure and with a roar Bratty charged.

“Sh-shit!” Beta gasped dodging to the left as the sword swung at him. “What the hell!? You’re going to let them kill us!?” Beta gasped staring at Gaster. Gaster stared at him stonily.

“I _told_ you, you need to be able to defend yourself. You can’t always count on me being here or my reputation scaring off bloodthirsty lab techs. Now fight back and defend yourself,” Gaster growled. Beta swallowed hard.

Sans took a step back, his soul pounding. He only had one HP. If he got hit, he was dust. Gaster wouldn’t let them kill him, would he?

“. . .Me or them, it’s me or them,” Catty whispered to herself. She seemed to be pumping herself up. Bratty swung her sword at Beta again and again, she seemed to be cheating, not letting Beta have his turn in the FIGHT. Beta had summoned a blue spear to block the eager attacks, sweat began dripping down his plum colored face.

“Sorry, kid!” Catty hissed and she charged at Sans, sharp claws extended. Sans dodged to the left and she growled, hitting the floor. She hissed her fur raising and a red whip appeared in each hand. She swung them at Sans and he ducked and dodged, panting. This was more of a workout than he was ready for.

“Ah- fuck!” Beta yelled as a sword sliced his arm and his eyes widened as red blood spilled from the deep cut. Gaster didn’t so much as blink, seeming to watch the fight with detached boredom.

Beta slammed his spear across the alligator's face and she yelped, falling back. Sans jumped back as a whip cracked in front of him and the other sliced above him. Sans panted hard barely rolling out of the way. He did not have the stamina to keep dodging like this. But. . .

“Good, B-4,” Gaster praised. “Sans. _Fight back._ ”

“No!” Sans growled. Gaster’s face darkened, his sockets narrowing. Sans swallowed hard and he dodged again as the cat monster’s whips cracked at him. “I won’t! _I won’t_!” Sans said.

“Ah!” Beta yelped, Bratty’s sword stabbing into his side. The fish boy’s eyes widened, and dust and blood sprayed from his mouth as he slumped.

“Beta!?” Sans’s eyes widened. Bratty’s grin twitched, growing wide.

“Sorry kid,” Bratty slid the sword out and Beta fell to the floor with a groan. Sans quickly checked his friend.

***BETA**

**LV 1, 20 ATK, 25 DEF, HP 3/30**

**_* Is very hurt_ **

**_*You know you have to help your best friend._ **

“I’ll make it quick,” Bratty growled raising her sword. Gaster was still watching, his expression unreadable. He wasn’t going to intervene. Sans’s soul pulsed anxiously, and he clenched his fists. The sword swung down-

A wave of bones smacked into the alligator monster throwing her back. Catty lunged at Sans and another of his bone attack slammed against her like a baseball bat, throwing her into the wall.

“Back. off.” Sans growled his magic burning within him. The sound of a blaster resounded throughout the air, and Sans felt his right eyelight going out, his left burned with the magic bubbling inside of him. Gaster leaned forward, his interest finally captured.

“LIke...we are sorry,” Bratty gasped staring at the giant dog like skull aimed at her in terror.

“Totally sorry,” Catty agreed, sounding far more sincere. Sans grit his teeth and watched as the skull’s maw opened wide with a ball of energy growing.

“Like, please don’t kill us!”

**Notes for the Chapter:**

> I *FINALLY* figured out how to get wingdings in here! YES. 
> 
> Translation: Star dammit B-4. I hate you so much, you little shit. Why is a mind as brilliant as mine cursed to deal with this little heathen’s atrocities to machinery? 
> 
> Catty and Bratty are some of my favorite NPCs ;D
> 
> Next chapter someone gains LOVE, and we might learn a bit more about certain humans(?).


End file.
